Materials and Methods: Ecological requirements and ethno-pharmacological survey were obtained in many field observation through interviews with practitioners and housewives in September 2013. The ripen seeds of Nigella sativa were collected from its natural habitat (560 m) in North east of national park of Golestan and ethanolic extract was obtained by maceration. Total phenolics (TPs) and total flavonoids (TFs) contents were determined spectrophotometrically and antioxidant activity was measured by 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging method.

Results: Nigella sativa is usually grown wildly in a small region of the national park of Golestan (500-760 m), that has an average rain fall of 575.9-614.8 mm, Ec (electrical conductivity of soil) 0.73 in sandy loam soils. The TP content is 121.3 ± 0.3 mg GAE g-1, TF contents was 194.04 ± 1.65 mg QUE g-1 and antioxidant activity (IC50) was measured in 0.13 ± 0.05 mg/ml-1. Results showed that the seeds of Nigella sativa has high content of TP and TF compounds as well as antioxidant activity, confirming the traditional use of Nigella sativa by rural healers as analgesic, anti-inflammatory, antiseptic, anticonvulsant, antidiabetes and antitumour agent against breast cancer, hypertension and hyperglycaemia in north of Iran.

Conclusion: Our results demonstrated that the seed extract of Nigella sativa L. could have good antioxidant potentials to prevent or control free radicals, which can produce many current inflammatory diseases such as cancer, diabetes, coronary diseases, infection, etc. So these data confirm the traditional use of this plant with its terpenoides, flavonoid and phenolic compounds.